Production of Carbon Clusters (Carbon Nanotubes, Fullerenes and Carbon Capsules) under Gravity-Free Condition

As new functional carbon material, carbon clusters such as fullerenes, carbon nanotubes (CNTs) and carbon capsules are very attractive, and efficient and high-quality production of carbon clusters is an important research target. In production of these carbon clusters by the arc-discharge method under sub-atmospheric pressure, gravity (heat-convection) strongly influences on the production. Under gravity-free condition, the diffusion speed of carbon molecules becomes very low, and the reaction time of the clusters under hot-gas atmosphere could be much larger (the cooling rate is much lower). Here, the effects of micro-gravity in the parabolic-flight experiment of production of carbon nanotubes, fullerenes and carbon nano-capsules are presented.